Estrogens compounds

Figure 10.1-13. Distribution of compounds in the layer of estrogenic compounds.

Much controversy has arisen regarding the ability of mixtures of weakly estrogenic compounds to act synergistically, notably the synergistic potential of mixtures of PCBs or of the insecticides dieldrin and toxaphene. " Recent studies suggest that the action of mixtures is at least additive. "... 

In assay sytems, many of these phytoestrogens are able to bind more avidly to the estrogen receptor than estrogen itself. Why plant products should possess such avid estrogenic compounds is unclear, but it has been suggested that consumption of phytoestrogens by insects may result in alterations in the sex... 

Exposure to estrogenic compounds through diet will differ for herbivores and carnivores, the latter being most likely to encounter endogenous steroids in their prey. Efficient uptake of steroids in mammals is illustrated by the use of the contraceptive pill, but routes of absorption in invertebrates remain to be determined. The relationship between endocrine disruption and metabolic toxicity, with reduced reproductive viability a secondary consequence of metabolic disturbance, also merits further study in invertebrate species. 

Legler J, van den Brink C, Brouwer A, et al. 1998. Assessment of (anti-)estrogenic compounds using a stably transfected luciferase reporter gene assay in the human T47-D breast cancer cell line. Organohalogen Compounds 37 265. 

There has been some speculation that estrogenic compounds may adversely affect the fertility of men by reducing testosterone levels and sperm counts (Atanassova et al, 2000). To date, however, the limited information available suggests that consumption of phytoestrogens does not affect reproductive hormones or semen quality (Nagata, 2000 Nagata et al., 2001 Mitchell et... 

Pillon A, Boussioux AM, Escande A, Ait-Aissa S, Gomez E, Fenet H, Ruff M, Moras D, Vignon F, Duchesne MJ, Casellas C, Nicolas JC, Balaguer P (2005) Binding of estrogenic compounds to recombinant estrogen receptor-alpha application to environmental analysis. Environ Health Perspect 113 278-284... 

Furuichi T, Kannan K, Suzuki K, Tanaka S, Giesy JP, Masunaga S (2006) Occurrence of estrogenic compounds in and removal by a swine farm waste treatment plant. Environ Sci Technol 40 7896-7902... 

Cargouet M, Perdiz D, Mouatassim-Souali A, Tamisier-Karolak S, Levi Y (2004) Assessment of river contamination by estrogenic compounds in Paris area (France). Sci Total Environ 324 55-66... 

Preparations suitable for replacement therapy are shown in Table 31-1. The oral and transdermal routes are used most frequently. There is no evidence that one estrogen compound is more effective than another in relieving menopausal symptoms or preventing osteoporosis. 

Perspectives in a global and European context. Anal Bioanal Chem 389 147-157 Hidy PH, Baldwin RS, Greasham RL, Heith CL, McMullen JR (1977) Zearalenone and some derivatives production and biological activities. Adv Appl Microbiol 22 59-82 Hodge EB, Hidy PH, Wehrmeisters HL (1966) Estrogenic compounds and animal growth promoters. U.S. Patent 3239351. March 8. 3p. 

Christiansen LB, Winther-Nielsen M, Helweg C (2002) Feminization of fish. The effect of estrogenic compounds and their fate in sewage treatment plants and nature. Environmental Project No. 729. Danish EPA, Copenhagen,http //www.mst.dk/homepage/... 

In general, the main pollution problems associated with surfactants can be summarized as (1) foaming in river and wastewater treatment plants [314,326, 344,348,349,356,357], (2) transformation to bioactive metabolites (i.e., poly-ethoxylated alkylphenols, estrogenic compounds) under aerobic and anaerobic conditions [315,356], and (3) formation of certain cationics which are toxic to microorganisms at high concentrations [356,357]. 

There has been some concern that the recently observed decline in sperm quality may be related to exposure to environmental estrogens (Sharpe and Skakkebaek, 1993) and at the same time there has been speculation that these estrogenic compounds may exert inhibitory effects against prostate cancer (Kurzer, 2002). Theoretically, exposure to high levels of dietary estrogens could alter the hypothalamic-pituitary-gonadal axis in men, but dietary studies to date have not shown such an hormonal effects. 

Many plants contain estrogenic compounds. Estrone (Fig. 11.11) is found in seeds of date palms, pomegranates, and apples, and estriol in willow. These may be merely by-products of sterol metabolism, or serve a particular function. Harborne (1993) proposed that plants synthesize steroid hormones to deter feeding by mammals. Estrogenic compounds in plants are thought to upset the delicate hormone balance of mammals. 

Methoxychlor is a weakly estrogenic compound that has been shown to alter fertility in male and female rats and cause development effects. Administration of lOOOmg/kg in the diet of pregnant rats caused vaginal defects in their offspring. Reduced fertility in both sexes was also noted when the offspring reached... 

Vitellogenin content VTG Reproductive endocrine parameter (Xeno-)estrogenic compounds Blood plasma of male fish 0-13... 

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